State aims to control, not stop, CWD

Two domestic white-tailed deer, possibly exposed to chronic wasting disease, jumped a fence and presumably are mixing with Pennsylvania's wild deer population just before hunting season.

There's a risk that the disease, deadly to deer and elk, may have jumped the fence with them.

The issue is more complicated than eliminating the two escapees.

Federal officials acknowledge that their 2009 goal of eradicating the disease in farmed deer and other cervids was "impractical" because of CWD's persistence in wild populations and a lack of knowledge about its transmission.

"We have now determined that our goal is to control the spread of the disease," said a U.S. Department of Agriculture rule published in June.

"There are areas in Colorado where this disease is so endemic that cervids will not survive in the wild," Pennsylvania State Veterinarian Craig Shultz said. "There's a concern about the long-term effect on the free ranging population. It doesn't mean large areas of the West are no longer compatible with deer. There are certain deer with a certain genetic makeup that are resistant."

Prions, the agents suspected of causing CWD disease, survive for years in the soil. The disease is transmitted by direct animal-to-animal contact through saliva, feces and urine.

Two state agencies manage white-tailed deer in Pennsylvania. An 8-foot deer fence delineates their authority.

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The Game Commission manages deer outside the fence - except for escaped property, and the state Department of Agriculture has managed deer inside farmers' fences since 2006 when the Legislature transferred deer farming oversight from the Game Commission.

Deer do not recognize the boundary. CWD can find its way between those outside and those inside. Wild and captive deer nuzzle at the fence.

Captives make a break for freedom.

"Like cows escaping into the wild, these deer are still the property of those farmers," said Jerry Feaser, spokesman for the Pennsylvania State Game Commission.

But unlike cows, captive deer do not show up twice a day for milking, according to State Veterinarian Craig Shultz. They are not handled daily.
Both hunters in Pennsylvania's $1.7 billion deer hunting industry and producers in the state's $100 million deer farming industry must cope with Pennsylvania's first CWD positives:

n Ronald Rutters, a deer farmer in New Oxford, was required in October to destroy his herd. The state Department of Agriculture may require others to follow. They lose the value of their animals, pay for the disposal and may face state-imposed restrictions on future agricultural use of their land.
n The Pennsylvania Game Commission has established a 600-square-mile disease management area in Adams and York counties. Hunters who get a deer inside the zone must check it at the Game Commission maintenance building on State Game Land 249. The agency will test the carcasses for CWD.

An estimated 750,000 hunters are expected to participate in Pennsylvania's two-week general deer season that starts Monday.

Agriculture and Game Commission officials stress that CWD has not been found in wild whitetail populations anywhere in Pennsylvania. If it were, the impact might not be economically devastating.

CWD was found in 2001 in Wisconsin, and the next season hunting license sales dropped 10 percent. Sales slowly regained some of the loss.
Richard C. Bishop, professor of agriculture economics at the University of Wisconsin-Madison, estimated that hunters spent $58 million to $83 million less on their sport in 2002, with lighter losses in subsequent years.

"Losses to the deer hunting economy will be counterbalanced as resident hunters who reduce expenditures spend their money elsewhere in the economy," he wrote. "Businesses that serve hunters are likely to feel the effects and this is especially true in rural areas as fewer urban deer hunters spend money on the services they provide."

A sociologist in Wisconsin found that if CWD seems contained, there is little hunter effect, according to the USDA Animal and Plant Health Inspection Service. If the disease becomes widespread, data in his study suggests that hunters will abandon the sport. Hunters from counties in which CWD positive animals were found were more likely to skip the 2002 gun season than were hunters from non-CWD counties.

Sampling suggests that infection rates range from less than 1 percent among wild white-tailed deer in Wisconsin to 15 percent among wild mule deer in northeastern Colorado, according to USDA APHIS. The agency has no estimate of CWD deaths in wild populations because there's no way to track them.

CWD has been at Pennsylvania's doorstep for years. The Game Commission and the Ag Department have been testing for years:

- The Pennsylvania Game Commission has been testing sick animals and random hunter kills since 1998. CWD was not detected in 38,000 tests. The commission tests enough deer to have 95 percent confidence that CWD is not in the wild population, according to spokesman Jerry Feaser.

- Deer farmers have been testing their fatalities since 2002. The tests were negative until two deer from Rutters' herd tested positive.

A live animal cannot be tested for CWD.

Pink 23, named for her ear tag, escaped on Oct. 18 when USDA wildlife shooters showed up at Rutters' farm. The Game Commission set up the disease management area around the farm.

"We're still looking for Pink 23," state agriculture spokeswoman Samantha Krepps said on Tuesday.

"Since the escaped deer was in a small herd and in a pen that already had two positive animals, the risk that the escaped deer is also exposed and may be shedding prions is much higher than the average deer," said David Wolfgang, Penn State Extension veterinarian. "Once the prions are in an environment they might be infectious for decades. We're really not sure, but it is a very long time. A susceptible deer would have to consume the prion in some way, but the possibility that CWD prions may be spread around the fields and woods is not a good thing."

Prions are abnormal cellular proteins that convert normal cell proteins in the central nervous system and lymphoid system to abnormal ones. Smaller than most viral particles, prions are assumed to resist normal disinfecting procedures.

"It's not an organism, so it doesn't have DNA," Shultz said. "It cannot be completely destroyed by incineration at high temperature. It's difficult to eradicate the disease in a traditional manner."

Crows can pass prions in their feces and so spread them from a CWD-infected carcass, according to a study by USDA's Gregory E. Phillips and Justin W. Fischer. Another study is looking at whether coyotes could do the same.

Pennsylvania's second escaped deer, Purple 4, got loose from a hobbyist who did not have a state permit to keep deer, Krepps said. Purple 4 had come to Gordon Trimer of Alexandria from the Rutters farm by way of another farm.

"Until that animal is determined to have CWD we have no plans to identify a disease management area in Huntingdon County," Feaser said. "We are concerned. We are looking into it. We have no jurisdiction over deer farms."

A second deer, not from Rutters' herd, also escaped Trimer's farm, according to Krepps.

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Jim Hook can be reached at 717-262-4759 and jhook@publicopinionnews.com.